100 The Mickoscope. 



and the "200,000" band should be seen, if resolved at all, as a 100,- 

 000 band similarly interlined. The extraordinary mechanical skill 

 of the maker and his success in ruling the lower bands attach real 

 interest to the plate, and to his methods of studying it, in respect of 

 the possibilities of line ruling and of extreme resolution; an interest 

 which is enhanced rather than diminished by the maker's easy faith 

 in the character and visibility of the highest bands and his inability 

 to apprehend the mechanical uncertainties and scientific absurdities 

 involved in this belief. If he has done even a small portion of what 

 he thinks, he has far surpassed all other experimenters, as far as yet 

 proved, and has earned and will receive the credit that he claims. 



Upon learning of the appointment of the committee, Mr. Fasoldt 

 tendered a request that he might be allowed to be present "when the 

 plate was examined," and kindly offered the use of his apparatus, 

 and also of his own services, to "show the lines" to the committee at 

 any time. Believing it to be of scientific as well as historic interest 

 and importance to know exactly what he saw and how he saw it, I 

 replied that while it would be impracticable for the committee as a 

 whole to make the proposed arrangement, as a member of the com- 

 mittee I would gladly accept his offer to show the lines, and that 

 the lines desired to be seen were those of the higher bands, from 

 " 120,000 " upward. No objection was made to this form of 

 acceptance. 



At an appointed time, one afternoon, the microscope was placed 

 in a wooden cabinet which nearly excluded daylight, and light from 

 a kerosene lamp with a large, flat wick, placed edgewise at a distance 

 of about two feet, was admitted through an opening in the cabinet 

 on a level with the nose-piece of the microscope. The stand was a 

 large and heavy one made by Mr. Fasoldt himself, with about ten 

 inches of tube-length including the objective, and furnished with a 

 Bausch and Lomb j'^ in. hom. imm. objective claiming 1.40 n. a., 

 and a 1 in. "perisoopic" ocular by the same makers. The illuminat- 

 ing rays were brought to a focus at the side of the nose-piece, and 

 about one-fourth of an inch from it, by means of a "watchmaker's 

 glass" of about two-inch focus mounted as a bull's-eye condenser, 

 the best effect being gained with an achromatic one said to have 

 been made for the purpose. The divergent pencil was then admitted 

 to the tube, and reflected downward through the objective by means 

 of a cover-glass internal illuminator, claimed and patented by Mr. 

 Falsoldt as his own. The peculiarity of this illuminator, aside from 

 the oddity of its large size and square shape, the substitution of 



